The invention relates to an arrangement made of substrate and superconducting film, a vortex diode including such an arrangement, and the use of vortex diodes for filters.
Resonators for filtering signals, such as e.g. cavity resonators, dielectric resonators, λ/2 resonators, and LC resonators are known from the prior art. It is disadvantageous that the known resonators are relatively large. Miniaturization of these filters is subject to limits because such miniaturization normally leads to a decrease in quality.
Filtering a plurality of frequency contributions is normally accomplished by splitting the signal into different channels. The signal in these channels is tested for the different frequencies using additional electronic devices. Alternatively, a complex method for scanning frequencies is known. In this case, as well, the need for downstream electronics and in some cases amplification of the output signal is disadvantageous.
Type II superconductors for filter purposes are known from the prior art. They completely displace a magnetic field until the value of the magnetic flux of Hc1<Hc, but remain superconducting up to a value of Hc2>Hc, Hc being the thermodynamically defined critical magnetic field strength.
In contrast to Type I superconductors, in Type II superconductors the magnetic field partially penetrates into the superconductor for fields at values between Hc1 and Hc2. Due to the quantum condition that applies for the magnetic flux and due to the energetically advantageous formation of normal superconducting limiting surfaces, the magnetic field can be present solely as vortices.
Vortices are microscopic objects having a normal conducting core a few nanometers in diameter and having a magnetic flux that equals exactly one flux quantum Φo (=2×10−15 Weber) in the superconductor. In cavities in the superconductor, such as e.g. in perforations or superconducting rings, the magnetic flux equals whole-number multiples of the flux quantum.
In order to use Type II superconductors as conductor materials, e.g. for magnetic coils or cables, they must be able to carry relatively large currents in the magnetic field with no losses. For this, the vortices are fixed locally via pinning centers. If they were not fixed, they would move through the superconductor when a current was applied due to the Lorentz force FL and would generate dissipative effects and thus an electrical resistance. Type II superconductors with such pinning centers are also called hard superconductors.
An arrangement made of substrate and superconducting film with perforations is known from DE 199 27 661 A1. The perforations anchor vortices. A high frequency (HF) filter having such an arrangement demonstrates improved HF resistance.
In the filters from the prior art, it is a disadvantage that a downstream electronic device is always needed that converts the signal to a usable DC signal. In addition, in the past it has not been possible to filter a plurality of frequency contributions from one signal simultaneously using the filters from the prior art.
Depending on the filter, for the conversion to a DC signal, the electronic device includes e.g. an HF converter adapted to the application or an HF power measuring device.
The object of the invention is to provide an arrangement made of a substrate and a superconducting film for a filter having direct conversion of the signal to a DC signal. It is a further object of the invention to provide a filter with which a plurality of frequency contributions can be simultaneously filtered out, without an electronic device downstream, and can be converted to a DC signal.